Bamboo Graded And Applications

There are a lot of wood constructions form, and the roof structure made with "I" joints has well prospects in china. The standards of wood constructions are important to developing the constructions, such as the Standard Specification for Evaluation of Structural Lumber Products (ASTM D 5456) and the Standard Specification for Evaluation and Monitoring Structural Capacities of Prefabricated Wood I-Joists (ASTM D5055). According two standards, the National Evaluation Report can be legitimated, and we need to follow the way.Bamboo has various properties in radial direction, and the properties can be divided into two classes, which are like the toughness fiber (the part of outside bamboo) and woods (the part of inside bamboo).Bamboo grad can be used to adjust the properties of laminated bamboo lumber (LBL), which the ratio of two classes will be changed, and the properties of LBL accord with the standard. The high class bamboo will be as face materials, and other can be used as core, so the properties of LBL will be improved.Referring to the producing mode of the China, bamboo can be graded, which are A, b, c, D, four classes, removing the outside and inside faces of bamboo.The MOE of "A" and "B" laminated bamboo lumber are higher than structure woods, but the MOE of C, D and mixture LBM are lower than the woods, so the LBL can not be used to replace the structure woods. The MOR of LBL is over the structure woods.The dimensions of LBL are very stabilization in high humidity surroundings, and three direction of swell are lower than woods, so the applications of vessel need to be discussed.Bamboo carbonized by vapor is widely used in bamboo floor, and the colors will be dark after the vapor carbonization, and resistant corrosion will be well. The density, MOE and MOR will be promoted after vapor carbonization, which needs to be researched more.The expensive price of LBL is the most problem on the application inconstruction, so it is impossible to replace woods with the LBL.The first right position of LBL is as the reinforced materials,. There are a lot of examples of Fiber reinforced Plastics (FRP) reinforced woos. The graded bamboos have excellent mechanical properties, which are similar with FRP. So the graded bamboo can be used as reinforced materials, to reinforced woods.The veneering composted with A class bamboo and pine has well mechanical properties, and the MOR of LVL with bamboo face is as 130-150% as normal LVL, and the MOE can be elevated into 9-25%.The bamboo and wood composites can be used in the max tension layer of glulam, which is as 3 times as the highest class wood and LVL, and the MOE also similar with the best woods.The graded bamboos and LBL has superiority in vessel productions, which are the high strength, stability of dimensional in water, well interface between bamboo and FRP, and anticorrosion.Because of the environmental protection, the FRP withdrew from the Europe and USA market. And the oil price is higher and higher. So, the best application of bamboo may be in replace the FRP and plastic.The high class bamboo has the properties of toughness fiber. The wire rod, section bar, sheet and block parts can be made with the long and short slice of bamboo by the pultrusion, the long rod and block mode, and sheet mode.The high class bamboo is similar with plastics in mechanical properties. The liquefaction of bamboo or rattan may replace the plastics and injecting to parts, which will be very interesting project.